How can I make a screenshot of a web page that scrolls off the screen?

Web Browser Based

• Super Screenshot — Captures a web page. Choose if it has to grab the full page (including the lower parts) or the top screen only

Firefox Add-ons

• Fireshot – Windows only, and I’m looking for an OS/X solution. I didn’t know Firefox add-ons could be OS specific.
• Screen Capture Elite – Version 1.0.0.12 – the capture full page doesn’t seem to work on frames, but if you make the internal frame its own page it captured the full page. Works on OS/X. Has several options including save to clipboard.
• Screengrab also appears to work on OS/X. It doesn’t have Save to clipboard option.

Standalone

• SnagIt for Windows ($49) is an all-around solid screen grabbing program

• Duck Capture For Windows Only (Free)